Winch mechanism for lowering a lifeboat, launch or the like, suspended from two falls, into the water and hoisting it out of the water

ABSTRACT

A winch mechanism for raising and lowering a lifeboat includes a main drive motor having multiple power paths to a pair of drums. Selectively operable clutches are used to complete the power paths when desired. A low speed power path and a high speed power path are included and the lower speed power path includes an overrunning clutch allowing the high speed power path to predominate if the clutches of both of these power paths simultaneously are operated. Two additional power paths are included, each associated with a respective drum to drive it at a higher speed than is effected either by the low or the high speed power path. Associated with each of these additional power paths is an overrunning clutch which allow the additional power paths to overrun the main drive. An auxiliary motor is associated with each drum for taking up slack in the cables reeled on the drums and an overrunning clutch associated with each such auxiliary motor allows the requisite auxiliary drive overrun. Additionally, a compensating control is used to maintain the boat level.

Tlriited States atet' Solter Jan. 29, 19741 ABSTRACT 1 1 WINCH MECHANISM FOR LQWERING A LIEEBOAT, LAUNCH OR THE LIKE,

A winch mechanism for raising and lowering a lifeboat includes a main drive motor having multiple power paths to a pair of drums. Selectively operable clutches Helmut Adolf Solter, Hamburg, Germany are used to complete the power paths when desired. A low speed power path and a high speed power path [73] Assignee: Schat Davits Limited, London, are included and the lower speed power path includes England an overrunning clutch allowing the high speed power path to predominate if the clutches of both of these [22] Filed: May 9, 1972 power paths simultaneously are operated. Two addi- [21] Appl. No.: 251,713 tional power paths are included, each associated with a respective drum to drive it at a higher speed than is effected either by the low or the high speed power path- Associated with each of these additional power [58] Fie'ld 184 paths is an overrunning clutch which allow the additional power paths to overrun the main drive. An aux- References Cited iliary motor is associated with each drum for taking up slack in the cables reeled on the drums and an over- UNITED STATES PATENTS running clutch associated with each such auxiliary FOREIGN PATENTS OR APPLICATIONS 9 4/1914 Smith motor allows the requisite auxiliary drive overrun. Ad-

ditionally, a compensating control is used to maintain the boat level.

1,024,699 2/1958 Germany 254/184 178,463 4/1923 Great Britain.....,................ 254/185 6 Claims, 2 Drawing Figures Primary ExaminerRichard E. Aegerter Assistant Examiner-Bruce H. Stoner, Jr.

Attorney, Agent, or Firm John P. Snyder et al.

WINCH MECHANISM FOR LOWEG A LIFEBOAT, LAUNCH OR THE LIKE, SUSPENDED FROM TWO FALLS, INTO THE WATER AND IIOISTING IT OUT OF THE WATER The invention relates to a winch mechanism on board a ship, drilling platform or the like, for lowering a lifeboat, launch or the like, suspended from two falls, into the water and hoisting it out of the water, with two drums for winding the falls, which drums are each provided with an auxiliary motor and with drive input means for imparting drive to each drum from a main motor. In using such a winch mechanism the most hazardous moments may occur during lowering and hoisting when the boat, launch or the like, suspended from the falls, is within reach of the waves. The equilibrium of the forces acting on the falls can then be seriously disturbed. In order to reduce the hazard it is necessary that each fall, and therefore each drum for winding the falls, can be operated separately and that the speed of any particular drum can very quickly be varied without causing jerks when the drive required for this is set in motion. When the boat is outside the reach of the waves, the two drums for the falls must have exactly the same speed.

The present invention provides a winch mechanism for a ship or drilling platform for lowering or lifting of a lifeboat or launch suspended from two falls into and out of the water, said winch mechanism comprising two drums for winding the falls, each of said drums being provided with an auxiliary motor and drive input means for each drum for imparting drive to the drum from a' main motor, the drive input means of the two drums being interconnected and each of said drive input means comprising at least two primary input shafts each connected through a friction clutch to the main motor and means, including a secondary input shaft, for interconnecting the primary input shafts to each other and to the drum so that a first of said primary input shafts, when driven at the rotational speed of the main motor, causes the drum to rotate faster than the second of said primary input shafts, said interconnecting means further including at least one free-wheeling clutch between the first primary input shaft and a part of the drive input means common to both the primary input shafts and a further free-wheeling clutch between each of the primary input shafts on the one hand and the drum and the auxiliary motor on the other hand so that at least one of said free-wheeling clutches is located between the secondary input shaft and an interconnected output shaft of the drive input means.

Because of the combination of free-wheeling clutches and friction clutches the drums can be driven at the same speed and also at different speeds. In order to accelerate a particular drum, it is merely necessary to engage a particular friction clutch, with the result that the drum in question is at once smoothly driven at a higher speed. It is therefore not necessary to disengage particular parts of the drive. The freewheeling clutches enable the drum to rotate faster while the original drive is maintained.

The second primary input shafts of the two drive input means may comprise one common shaft. Such an embodiment may provide a simplification in that one input shaft with its associated drive can be obviated.

The second primary input shafts of the two drive input means may be interconnected by a set of gear wheels, in which case one of the shafts comprises a separate freewheeling clutch. Such an embodiment of the winch mechanism may provide greater freedom in the possibilities for driving the drum. Thus, the gear wheels interconnecting the second primary input shafts of the drive input means, the gear wheel on a first of said primary input shafts may have a smaller diameter than the gear wheel on the second of said primary input shafts. There is thus an additional possibility for the faster driving of one of the drums in that the drive can be performed by means of each of the two input shafts.

In an advantageous embodiment of the invention the friction clutches may be provided with remotecontrolled electric, hydraulic or pneumatic controls. The friction clutches may be controlled from a central point.

The two drums may be connected, through a device for comparing the speeds of the drums, to the controls of the friction clutches for engaging and disengaging the friction clutch in one of the two first primary input shafts, depending on the speeds of the drums in relation to each other.

The invention will now be described, by way of example with reference to the accompanying drawings, in which:

FIG. 1 schematically shows a winch mechanism according to the invention,

FIG. 2 shows another embodiment of a part of the winch mechanism shown in FIG. 1.

In FIG. 1 the falls from which the boat (or the like) is suspended have the references 1 and 2. The fall I is wound on to a drum 3 and the fall 2 is wound on to a drum 4. The drum 3 is mounted on a shaft 5 on which a gear wheel 6 is also mounted. The gear wheel 6 engages with a drive pinion 7 which is mounted on a shaft 8 connected to a rotor of an auxiliary motor 9. At its other end the shaft 8 is connected to a freewheel 10 which is capable of engagement with a drive wheel 11. The drive wheel 11 can drive the freewheel 10 in a direction indicated by arrow 12, this being the direction of rotation of the drum 3 for winding up the fall 1, Le. the direction of rotation for hoisting the boat etc. The drive wheel 11 is attached to a shaft 13 on a pinion 14 which is mounted engaging with a gear wheel 15, the latter being attached to one end of a shaft 16 the other end of which is connected to a driven member 17 of an electromagnetic friction clutch. The driving member I8 of said friction clutch is connected by means of a shaft 19, to a gear wheel 20.

To the other end of the shaft 13 carrying the pinion 14 is attached a friction wheel 22. The friction wheel 22 engages with a drive wheel 23 on one end of a shaft 24 on the other end of which is disposed a gear wheel 25 which engages with a gear wheel 26 on a shaft 27. On the shaft 27 is disposed a freewheel 28 which engages with a drive wheel 29 attached to a shaft 30. A centrifugal brake 31 and a driven member 32 of an electromagnetic friction clutch are also attached to the shaft 30. The electromagnetic friction clutch is controlled by means of a magnet 33. A driving member 34 of the magnetic clutch also forms the casing of the centrifugal brake 31. The casing 34 forms is connected by means of a shaft 35 to a gear wheel 36. The gear wheel 36 is connected to the gear wheel 20 through an intermediate wheel 37.

In similar fashion as described in the foregoing for the drum 3, the drum 4 is connected by means of a shaft 38 to a gear wheel 39 which engages with a pinion 40, the latter being attached to a shaft 42 one end of which is connected to the rotor of an auxiliary motor 41. To the other end of the shaft 42 is attached a freewheel 43 which can engage with a drive wheel 44 attached to one end of a shaft 45. On the other end of the shaft 45 is mounted a pinion 46 which can engage with a gear wheel 47 on a shaft 48. On the shaft 48 is disposed a driven member 49 of an electromagnetic friction clutch, a driven member 50 of which is connected by means of a shaft 51 to a gear wheel 52. The electro magnetic friction clutch is controlled by means of an electromagnet 53.

The shaft 45 with the drive wheel 44 and the pinion 46 also has mounted on it a freewheel 54 which engages with a drive wheel 55 which is connected by means of a shaft 56 to a pinion 57. The pinion 57 engages with a gear wheel 58 mounted on a shaft 59. A driven member 60 of an electromagnetic friction clutch is also disposed on the shaft 59. A driving member 61 of the electromagnetic friction clutch is connected to a gear wheel 63 by means of a shaft 62. The gear wheel 63 engages with the gear wheel 36. The electromagnetic friction clutch is controlled by means of an electromagnet 64. The gear wheel 63 also engages with a gear wheel 65, and the latter also engages with the gear wheel 52. Through an intermediate wheel 66 the gear wheel 52 cooperates with a pinion 67 mounted on a shaft 68 which is connected to the rotor of a main motor 69. The main motor 69 is provided with an automatic brake 70.

The gear wheels 67, 66, 52, 65, 63, 36, 37 and are driven by means of the main motor 69. Now if, for example, the electromagnetic clutch 32, 34 is engaged, the wheel and therefore also the wheels 58 and 57 are driven through the agency of the gear wheel 36, the engaged electromagnetic clutch, the freewheel clutch 29, 28 and the pinion 26. As shown in the drawing, the drums 3 and 4 are then driven at equal speed.

If the clutch 60, 61 is engaged, the gear wheel 58 is driven through the agency of the gear wheel 63. As a result, the two gear wheels 25, 26, and 57 are driven at higher speed, since the gear wheel 58 has a larger diameter than the gear wheel 26. Because of the freewheel clutch 28, 29 this fast drive can be obtained only by engagement of the electromagnetic clutch 60,61. The drums 3 and 4 are now again driven at equal speed.

If it is necessary, for example, to drive the drum 4 faster, the clutch 50, 49 is engaged. Now the gear wheel 52 drives the pinion 46 through the agency of the gear wheel 47, so that the drum 4 is driven at higher speed. This is possible, because the freewheel clutch 54, 55 comes into operation, so that the pinion 46 can rotate faster than the driven pinion 57. In similar fashion the drum 3 can be driven faster by engagement of the magnetic clutch 17, 18. To increase the speed of the drum it is therefore merely necessary to engage a friction clutch, and there is no need to disengage any other drive. Thus very rapid control and very smooth acceleration are obtained.

As FIG. 2 shows, it is also possible to omit the shaft 59 together with the clutch 60,61 and the shaft 62. The drums can then be driven at a low speed through the agency of the shafts and 27 and the clutch 32, 34. The faster drive by means of shafts 62 and 59 is then obviated. Instead of electromagnetic clutches, hydraulic or pneumatic clutches can be used.

When the clutches 17, 18, 60, 61 and 49, 50 are deenergised, the drive is slowed down only. If the clutch 32, 34 were to be de-energised, the load would still be held by the centrifugal brake 31. The main motor 69 with the brake 70 in fact carries the load of the wind mechanism. The brake 70 is relieved when the motor is energised. When the motor is not energised, the brake 70 operates automatically.

The auxiliary motors 9 and 41 ensure, when switched on, that in the event of a slack in the falls 1 and 2, the falls are very quickly drawn taut. The freewheel clutches l0, 1 1 and 43, 44 allow this fast rotation of the drums. The auxiliary motors 9 and 41 are not powerful enough to wind up the falls 1 and 2 under load. On a rising wave, however, they can keep each fall taut. When the boat is on the waves, the electromagnetic clutches can be disengaged, so that when the boat descends on a descending wave, the winch mechanism lets the falls run out with rotating centrifugal brake 31, so that the boat is braked to some extent.

As FIG. 1 shows, there is additionally a compensating device.

A bevel gear wheel 71 is disposed on the shaft 5 of the drum 3 and a bevel gear wheel 72 is disposed on the shaft 38 of the drum 4. The bevel gear wheel 71 engages with a bevel gear wheel 73 mounted on one end of a shaft 74 which enters a rotatably mounted casing 75. On the other end of the shaft 74 is mounted a bevel gear wheel 76 which engages with a bevel gear wheel 77, a bearing of which is located in a wall of the casing 75. The bevel gear wheel 77 also engages with a bevel gear wheel 78 mounted on one end of a shaft 79, on the other end of which is disposed a bevel gear wheel 80 engaging with the bevel gear wheel 72. When the drums 3 and 4 rotate at equal speed, the casing 75 will be at rest. Externally the casing 75 comprises a gear ring 81 which engages with a pinion 82 mounted on a threaded spindle 83. The threaded spindle 83 engages with a nut 84 which cooperating with a conducting rod 86 and a conducting rod 87. The rod 86 is connected to the electromagnetic clutch 17, 18 and the rod 87 is connected to the electromagnetic clutch 49, 50.

If the drum 4 is, for example, driven faster than the drum 3, e.g., because the boat is lifted by a wave, the casing 75 will rotate and the screw spindle 83 will be driven. As a result, the nut 84 will move to the left and contact will touch the conducting rod 86. This causes the clutch 17, 18 to engage, so that the drum 3 is driven faster. The nut 84 will then therefore move to the right, and as soon as it has returned to its initial position of rest, the clutch 17, 18 is disengaged. The position of rest of the nut 84 corresponds to a horizontal position of the boat. This is therefore an automatic device for bringing the boat into the correct position.

What I claim is:

1. A winch mechamism for a ship or drilling platform for lowering or lifting of a lifeboat or launch suspended from two falls into and out of the water, said winch mechanism comprising two drums for winding the falls, each of said drums being provided with an auxiliary motor and drive input means for each drum for imparting drive to the drum from a main motor, the drive input means of the two drums being interconnected and each of said drive input means comprising at least two primary input shafts each connected through a friction clutch to the main motor, and means, including a secondary input shaft, for interconnecting the primary input shafts to each other and to the drum so that a first of said primary input shafts, when driven at the rotational speed of the main motor, causes the drum to rotate faster than the second of said primary input shafts, said interconnecting means further including at least one free-wheeling clutch between the first primary input shaft and a part of the drive input means common to both the primary input shafts and a further freewheeling clutch between each of the primary input shafts on the one hand and the drum and the auxiliary motor on the other hand so that at least one of said first-wheeling clutches is located between the secondary input shaft and an interconnected output shaft of the drive input means.

2. A winch mechanism as claimed in claim 1, wherein the second primary input shafts of the two drive input means comprise a common shaft.

3. A winch mechanism as claimed in claim 1, wherein the second primary input shafts of the two drive input means are interconnected by a set of intermeshing gear wheels and one of said second primary input shafts is provided with a separate free-wheeling clutch.

4. A winch mechanism as claimed in claim 3, wherein a gear wheel on a first of said second primary input shafts has a smaller diameter than that of a gear wheel on the second of said primary input shafts.

5. A winch mechanism as claimed in claim 1, wherein said friction clutch means include remote-controlled controls.

6. A winch mechanism as claimed in claim 5, wherein the two drums are connected, through a device for comparing the speeds of the drums, to said controls of the friction clutches for engaging and disengaging the friction clutch in one of the two first primary input shafts depending on the speeds of the drums in relation to each other. 

1. A winch mechamism for a ship or drilling platform for lowering or lifting of a lifeboat or launch suspended from two falls into and out of the water, said winch mechanism comprising two drums for winding the falls, each of said drums being provided with an auxiliary motor and drive input means for each drum for imparting drive to the drum from a main motor, the drive input means of the two drums being interconnected and each of said drive input means comprising at least two primary input shafts each connected through a friction clutch to the main motor, and means, including a secondary input shaft, for interconnecting the primary input shafts to each other and to the drum so that a first of said primary input shafts, when driven at the rotational speed of the main motor, causes the drum to rotate faster than the second of said primary input shafts, said interconnecting means further including at least one freewheeling clutch between the first primary input shaft and a part of the drive input means common to both the primary input shafts and a further free-wheeling clutch between each of the primary input shafts on the one hand and the drum and the auxiliary motor on the other hand so that at least one of said first-wheeling clutches is located between the secondary input shaft and an interconnected output shaft of the drive input means.
 2. A Winch mechanism as claimed in claim 1, wherein the second primary input shafts of the two drive input means comprise a common shaft.
 3. A winch mechanism as claimed in claim 1, wherein the second primary input shafts of the two drive input means are interconnected by a set of intermeshing gear wheels and one of said second primary input shafts is provided with a separate free-wheeling clutch.
 4. A winch mechanism as claimed in claim 3, wherein a gear wheel on a first of said second primary input shafts has a smaller diameter than that of a gear wheel on the second of said primary input shafts.
 5. A winch mechanism as claimed in claim 1, wherein said friction clutch means include remote-controlled controls.
 6. A winch mechanism as claimed in claim 5, wherein the two drums are connected, through a device for comparing the speeds of the drums, to said controls of the friction clutches for engaging and disengaging the friction clutch in one of the two first primary input shafts depending on the speeds of the drums in relation to each other. 